Telegraph transmitter



-0i.29,194o. p m v 2,219,904

TELEGRAPH TRANSMITTER Original Filed Dec. 31, 1936 Z'Sheets-Sheet 1 FlG.l

.-|lll|" ...nnllllllllllllllllllllIll INVENTOR. LOUIS M. POTTS ATTORNEY.

Patented oee so. 1940 PATENT OFFICE TELEGRAPH TRANSMITTER Louis M. Potts, Evanston, 11]., assignor to Teletype Corporation,

' Delaware Chicago, 111., a corporation of Application December a1, 1930, Serial No. 118,516 a Renewed May 20, 1939 2.1 Claims. (01. 178-79) The present invention relates to telegraph apparatus and is concerned more particularly with keyboard mechanisms for the transmission of synchronized monopulse signals.

The principal object of the present invention is the provision of a transmitter of simple and compact design, which is positive and efficient in its operation and inexpensive in construction.

A feature of the invention resides in the transmission of monopulse synchronous signals having an interval of predetermined constant duration in which its characteristic is distinguishable by its period of occurrence relative to a synchronously controlled cyclic period.

In its essential embodiment, the present invention contemplates a transmitting mechanism especially adapted for generating monopulse synchronous code signals to be used in the control and'operation of telegraph printers of the class maintained in a non-interference position, is

designed to be shifted slightly upon the operation of its associated manual key. A particular key upon being actuated also causes to be dislodged a locking means which intervenes to prevent the actuation of any other key during the time that the particular key is actuated. When, after a key operation-arevolving seeker carried by the synchronously controlled shaft encounters the dislodged interposition element, it causes to be momentarily opened a pair of contacts and also after the lapse of a constant time interval to be restored both the interposition element as well as its associated actuating key. The period durin each synchronized cycle when the aforedescribed circuit interruption or signal occurs characterizes the letter. figure, or other function which has been selected.

For a more comprehensive understanding of the several features and the structure of the present invention, reference should be had to the accompanying drawings and to the following detailed specification wherein like reference characters have been 'employedto designate corresponding parts throughout, and wherein;

Fig. 1 is an exploded perspective view of a transmitter apparatus having embodied therein certain principles concerned in the vention;

Fig. 2 is a cross-sectional view taken approximately on line 2-.2 of Fig. 5;

Fig. 3 is a fragmentary side elevational view 5 of the mechanism shown in Figs. 2 and 5 with the cover wall broken away;

Fig. 4 is a diagrammatic chart which graphically shows atypical signal (the alphabetical character K) such as isemployed in the con- 10 .trol of apparatus for which the present invention is particularly adapted; and,

Fig. 5 is a plan view of a transmitting mechanism such as is featured in the foregoing figures having certain portions thereof broken away to, reveal the posterior structure.-

In the drawings the reference character ll denotes a cylindrical cup which serves as a housing and with its bottom wall I! completely surpresent inrounds the transmitter operating mechanism. A 20 cover plate I; is fitted over. the brim of the housing cup II, and therethrough arranged in concentric circles are two rows of manual keytops I 4. The outermost row of keytops have vertically extending bars IS with short cam projection I6, 25

while the innermost rows have corresponding ba'rs I'I (left side of Fig. 2) with longer cam projection Ill. The difference in the length between projections I6 and I8 is sufllcient to compensate for the diflerence in the respective distances between the center of the unit and the two rows of key bars so that the extremities of projections 88 extend out and align peripherally with the extremities of projections l6.

In a circular arrangement about the vertical 35 bars l5 and I! are a plurality of interpositioned elements or signal actuators I 9, each one of which is associated with one of the key bars IE or I! and has acam projection 2i that aligns with and abuts the extremity of the aforementioned projections l6 and 18. A garter spring 22 which encircles the several interposition elements I9, urges them inwardly until their cam projections 2| are butted against the keybar projections l6 and I8. While in this position, the oifset extremity 24 of each bar I! or H is disposed beneath the skirting flange of bell disc 63,

and its vertical or main body portion is withheld against the influence of garter spring 22 so as accurate centersespecially since their vertical suspension is dependent upon the support afforded by cross pins 23. This construction has been found satisfactory in operation, and by reason of its simplicity, to be economical in manufacture and assembly.

The extremity of each key bar I5 and I1 is angularly bent at 21 as may best be noted in Fig.

' 3, and the extremity of each bent portion 21 'lies above an associated opening 23 in a locking disc 23 when said disc is in its normal (counterclockwise extreme) position. The several openings 23 are staggered to correspond with the disposition of the several extremities 21, and upon the actuation of any key bar |5 or l1, the engagement between the foremost surface of its inclined portion 21 with a contiguous surface on a deflected portion 3| struck to form the opening I 23, causes locking disc 23 to be cammed in a clockwise direction, as viewed in Fig. 5, in opposition to its return spring 32 which is anchored at 33 to a relatively stationary portion of the unit. disc 23 causes to be offset its several openings 28 sufllciently so that all of others of them, excepting the one which has been entered by the actuated key bar, are no longer in alignment with their associated angled portion 21, and if thereafter any other key bar |5 or H is attempted to be depressed, the operation is blocked when the extremity of its angled portion21 abuts the solid surface of the locking disc 23.

Upon the depression of a key bar and the consequent rotation of the locking disc 23, the condition' thus established is latched momentarily pending the transmission of the signal which is not executed until a seeker yoke 41 passes the proximity of the depressed key bar and its related interposition element iii. The lowermost shoulder of cam projection 2| overlies the upper shoulder of key bar projections l3 or I8 when the former is in its innermost or effective condition, and thereby prevents return spring 62 from restoring the actuated key bar, and since the garter spring 22 urges interposition elements I9 inwardly, this latched condition prevails until said interposition elements l3 are restored to normal by a device to be described later.

Secured by means of the screws 333 to the cover plate I3 is a supporting disc 34 whose radial flange 35 is slotted at several places 33, Fig. 5, to receive innermost the vertical interposition bars l5 and I1 and outermost the interposition elements l9 aforedescribed. Between the rigid disc 34 and cover plate I 3 there is firmly gripped a thin supporting disc 31 which is also radially slotted in alignment with the aforementioned slots 33 to receive the vertical bars I5 and H as well as interposition elements l3. Accordingly, with the slots in radial flange 35 and those in supporting disc 31 affording lateral support to the several elements |5, l1, and l3, a relatively flexible assembly unit having nevertheless few moving parts is attained.

In the featured embodiment, a bushing 38 is fitted through discs 34 and 23 which serves as a journal for the extremity of a synchronously This rotational displacement of locking driven shaft 33 and has a pivot sleeve for the reciprocable discs 23, 33-, and a slidabie disc 4| to be. described later. As shaft 3| rotates, it carries with it a collar 42 which is secured to it by means of a set screw 43, and the arm 44 which is integrally formed with the collar 42. Upon arm 44 is mounted a trunnion block 45 through which extends the shaft 43 and the ends of the latter protrude through a pair of ears 50, Fig.. 1, which are integrally formed with the shafts 43 of a yoke 41, Fig. 1. In this arrangement, yoke 41 is supported for limited reciprocal movement by an adjustment screw 43 whose head protrudes through a small opening in the yoke 41, and determines the clockwise limit of movement, while the comers of the pivotal ears of shafts 43 limit the counterclockwise extent of movement of yoke 41. The shafts 43 of yoke 41 straddle the bushing 33 and terminate with slightly upturned nibs which rest against the bottom of slideable disc 4|. The main shaft of yoke 41 extending radiallyfrom the pivotal center of the assembly terminates with a T-shaped structure which supports two cam elements. A vertically acting cam body 5| is a narrow segment whose fore portion flares downwardly and is disposed to ride, under the offset extremities 24 of any interposition element I3 which is found in its selected or innermost position. Since the plateau section of cam 5| is normally in horizontal alignment with the projections 24, as may be noted in Fig. 2, it will be understood that in the event any key member I4 is depressed at the instant when the response of its interposition element I3 in moving inwardly would encounter the plateau section of cam segment 5|, the blocking of the square shoulder 24 by said plateau section of segment 5| will prevent -the instantaneous selection or movement into selected position of such interponent I9 but instead will put off the selection until the seeker 41 shall have passed the proximity of such interponent l9. The contingency of such an occurrence, however remote, must be noted as possible and in order to prevent the consummation of an interponent selection under these circumstances and the resultant fore-shortening of the signal period, the peripheral surface of cam segment 5| is utilized in the momentary blocking of the selector. passes the proximity of such interponent l9, however, the latter is free to resume its normal movement under impetus of the garter spring 22, so that upon the subsequent passing-by of the seeker, itscam 5| will ride under projection 24 generating a full length signal in the normal manner of operation. Another cam 52 is provided with a sidewardly inclined surface 53 which, as the assembly rotates (clockwise as viewed in Fig. 5), engages the adjacent surface of offset extremity 24 and cams the latter outwardly and back into its normal or non-active position.

Extending perpendicularly from the slideable disc 4| are three parallel guide legs indicated 54, 55, and 53. The three legs extend through snugly chambered openings in the supporting disc 34 and maintain parallel vertical movement of slideable disc 4|. One of the legs 54 terminates with a contact .actuating projection 51 which, when slideable disc 4| is moved upwardly, causes, through its engagement with an insulated block on the contact element 58, an electricalseparation of the latter from its associated contact element 53. After cam 5| has passed over the offset extremity 24, cam 52 inaugurates the restoration Immediately that the cam segment i of a particularly selected interposition element I 9, and when finally restored, cam rides on the projection 24 and resumes its normal position under impetus of a set of springs 6| oneof which surrounds each of the guide legs 54, 55,

- and 56, urgingthe slideable disc 4I downwardly Ily maintaining them aiar, may be employed in I accordance with a reverse system of operation where the normal line is open and the signalinterval constitutes a closed or current line condition. I

A bell disc 63 is supported immediately beneath locking disc 29 for limited reciprocal rotation about bushing 36. The two discs 29 and 63 are held by a pair of shouldered screws which may be threaded into the supporting member 34 and which extend through arcuate'slots in both discs 29 and 63. The periphery of bell disc 63 is studded with spaced lugs 64 each'associated with one of the interposition elements I9. A spring 65, Fig. 5, connecting an car 66 integrally formed with bell disc 63 and one 61- integrally formed with looking disc 23, urges disc 63 in a counterclockwise direction and disc 29 in a clockwise direction until a pin 36 which extends perpendicularly from disc 29 into an elongated slot 46 of the bell disc63 strikes the leftward extremity, Fig. 5, of said slot. While, as will be noted later, spring is tensioned by the movement of disc 29 clockwise and pulls disc 63 in the same direction,

the restoration of disc 29 is not through spring 65 but rather through the .tenser spring 32.

Upon the ,camming out of an interposition element I9 restoring itto its normal position, cam projection 21 is withdrawn from interfering with the projection of its associated feed bar I5 or IT. Accordingly, the latter is also freed as a consequence of the primary stimulus initiated by yoke 41 and thereupon responds to the urge of its individual return spring '62, resumes its normal position, and withdraws its angled portion 21 from resting against the deflected portion 3| of locking disc 29. The freeing of disc 29 permits it to respond to the return spring 32 rocking counterclockwise or until the several openings 28 are again brought into alignment with the angled portions 21 of all of the key bars I5 and I1.

The stop means 36. for limiting the counterclockwise movement of locking disc 29, Fig. 5, which passes through an elongated hole 40 in disc 63 serves merely for limiting the counterclockwise movement of disc- 29 with respect to disc 63 but for limiting the counterclockwise movement of both of said discs, suitable limiting pins are contemplated which may pass through elongated holes in both discs or in disc 63 alone and which are anchored in the supporting disc 34. When locking disc 29' is urged clockwise pursuant to the depression of a key bar I5 or' I1, tension is stored in spring 65 and by it in turn communicated to bell disc 63, but there movement is resisted when a tooth 68 inte rally formed with slideable disc 4| encounters a floating lug 69 which is carried by a strip of spring steel II secured to the bell disc 63 at I2. When a key bar is depressed, the resultant clockwise movement of locking disc 29 distends the restore.-

tor spring 32 as well as spring 65.

In its normal position, ,bell disc 63 is so disposed that the peripheral notches thereof which intervene the lugs 64 align opposite the ends 24 of interposition elements l9.permitting any one of the interposition elements I9 to assume readily its effective condition upon the actuation of its associated key bar I5 or I I. Thereafter, when slidableidisc M is raised bythe action of yoke 41, floating lug 69is freed, and accordingly bell disc 63 is permitted to rock in a clockwise direction as influenced by spring 65 until the particular tooth 64 adjacent to the actuated one of the interposition elements I9 encounters and is arrested;

thereby. An interposition element I9 is cammed out by the side cam 52, and when its tooth 24 clears the lugs 64, bell disc 63 is free to move farther in a clockwise direction presenting a lug 64 directly behind the element I 9 and preventing said element from resuming its selected position after the side'cam 52 has moved by. This it would otherwise tend to. do especially if a key bar I5 or II happened to be continuously depressed as by a lingering manipulation.

Accordingly, the function of bell disc 63 will be observed as one of preventing a multiplicity of signals from being issued in response to a single prolonged key bar actuation and requiring insteadthat, where a number of signals aredesired, an operator be required to impart a corresponding number of manipulations. recalled that upon rotating locking disc 29 clockwise, a certain tension was stored up in the res- Operation The embodiment of the present invention herein disclosed contemplates, as has beensaid, a mode of signal transmission which may be best understood by referring to the accompanying Fig. 4 where a cycle of rotation of shaft 39 may be interpreted as the linear distance between any one of the alphabetical or numerical characters illustrated in this figure, and the point thereafter at which that character first recurs. When no signals are transmitted, a cqntinuous current condition prevails which is symbolized by the shaded-section I3 occurring above the median line 14. On the other hand, during a signal interval, the current condition is interrupted and is indicated in Fig. 4 by the shaded section I5 occurring below the median line 74. The length of the signal interval I5 is dependent, of course, upon the interval duration between the instant when offset extremity 24, acting upon cam 5|, cause yoke 41 to raise disc 4i and its leg 54 sufficiently to break the connection between the contact bar 58--59 and the instant when sideextent, as indicated by the length of the shaded section 15 illustrated in Fig. 4, in order that the created line signals may not tend to become weakened. This practice limits the closeness of consecutive signals to such a minimum that at least five characters, in terms of radial distance, are required to intervene consecutive transmitted character signals, and where characters more closely situated upon the transmitter periphery are attempted their transmission may accordingly require separate cycles of transmitter rotation.

The depression of any key bar l5 or II is effected by pressing the finger upon one of the manual keys I which carries upon its upper surface a legend indicating the character which it represents. In response to the downward movement or the key bar proper, two results are obtained. In the first place, locking disc 2 9 is cammed clockwise, as viewedin Fig. 5, and in prompt succession an associated interposition element I9 is afforded a clearance by the withdrawal of the key bar projection IE or l8 so that garter spring 22 will urge said particular interposition element I! centripetally into its effective position whereat its lowermost extremity 24 will occupy a space between two of the spacing lugs 64.

Meanwhile, it will be recalled, shaft 38 is in continuous rotation carrying with it yoke" which seeks out any selected interposition element I9, and upon encountering one of them in its centripetal station, is cammed away causing to be tilted its inwardly extending shafts 49. The clockwise rotation of locking disc 29 imparts a tension to spring because its other end, which is secured to ear 66, fails to respond and follow in the clockwise movement of locking disc 29. This is due to the blocking engagement of floating lug 69 and tooth '68 of slideable disc 4 l As the shafts 49 of yoke 41 tiltupwardly, they cause to be hoisted the slideable disc ll until pro- Jection 6B is moved clear ofthe floating lug 69, while at the same time contact, actuating projection 51 encounters and opens the contact pair "-59. As a result of the freeingof bell disc 63, the latter rotates about a half tooth distance (about half the width of one of the spacing lugs or teeth SI). The period occupied by cam- 5| in passing the proximity of the interposition element l9, while relatively short, is equivalent nevertheless in the present embodiment to the peripheral distance of approximately five consecutive interposition elements l9. Towards the end of the period of its effective encounter, with an. element l 9, side cam 53 moves away the selected interposition element I! which had been occupying the space between consecutive teeth or lugs 64 permitting bell disc 63 to move the remainder of a short angular distance, and in so doing to prevent the particular element is from reentering. The

purpose of blocking lug "68 therefore will be understood as one of preventing the rotation of bell disc 63 in response to the urge of spring 65 until after a particular interponent l9 has had an opportunity to enter its associated peripheral clearance between a pair of lugs 6.

Following this, theslidable disc 4| is elevated, latch tooth 68 removed from the field, and the force of spring 65 permitted to rotate bell disc 63 until its progress is retarded by the extremity of the very interponent 19 which had selected. After said interponent is-displaced by the side cam 53 and thereby caused toresume its normal position, bell disc 83 is permitted to move farther in the clockwise direction as urged by spring 68 so that the interponent it having been cammed out may not reenter and permit a second signal to be generated. A plurality of depressions of the manipulators I! or H is therefore essential to eflect a plurality of character signals, and the continued depression of any of said manipulation plungers does not produce more than one signal.

The restoration of the particular interposition element l9 withdrawing its cam projection 2| permits its associated key bar I! or I! to respond to the urge of its return spring '62 and resumes its elevated or normal position in readiness for a succeeding operation.

While the present invention has been explained and described in contemplation of a specific embodiment, it is to be understood that numerous modifications and variations may be made without departing from the spirit of the present invention. Accordingly, it is not intended to be limited to the specific details of the accompanying drawings nor to the language of the foregoing specification except as indicated by the hereinafter appended claims.

What is claimed is: I

1. A transmitter including a plurality of key bars arranged in a circle, a disc having a plurality of vanes each associated with one of said key bars, and actuating means carried by each key bar for rotating said disc by engagement with a vane to prevent the actuation of any other of said key bars pending the restoration of an actuated key bar.

2. In a keyboard transmitting mechanism, a circuit breaker, a plurality of key bars, a correswnding plurality of circuit breaker actuating means, each under the control of one of said key bars, and a device actuated by a conditioned one of said plurality of actuating means for operating said circuit breaker and for restoring said conditioned one of said plurality of actuating means.

3. The combination set forth in claim 2 in which said operating device includes means to both operate said circuit breaker and restore one of said actuators within the same cyclic time intervals.

4. A keyboard transmitter mechanism, including a circular arrangement of manipulators, a circular arrangement of signal initiating elements each associated with and conditioned by one of said manipulators, a continuously revolving apparatus traversing the proximity of said signal initiating elements for impressing current conditions upon a line and actuable by a conditioned one of said elements, means under the control of said revolving apparatus for restoring each conditioned one of said elements following its control of said revolving apparatus, and means for preventing the reconditioning of one of said elements after its restoration in the event of a continuous operation of its associated manipulator.

by said longitudinally movable portion in accordance with its alternative positions, and a plurality of conditionable means arranged about said rotatable member for shifting said portion from one to another 0! its alternative positions.

6. In a transmitting mechanism, a circuit breaker associated with a signaling line, a rotatable member having a reciprocable portion, a plurality of manipulation means, an element under the control of each of said plurality of means for encountering said reciprocable portion and for rocking the latter to actuate said circuit breaker, and apparatus carried by said reciprocable portion for restoring any of said elements following its encounter by said reciprocable portion.

. 7. A keyboard transmitter comprising in combination, a plurality of key members, a circular arrangement of actuators controlled by said members, each having a key member latching portion and a trip portion, a revolving apparatus carrying a shiftable arm to be encountered by said trip portion, a line switch actuated by said shiftable arm when the latter encounters one of said actuator trip portions, and means carried by said revolving apparatus for restoring any of said actuators to a neutral position after the lapse of a predetermined time interval.

8. In a transmitting mechanism, a plurality of key members, a contact controlling device, means under the control of any one of said plurality of key members for actuating said contact controlling device, and a member responsive to a prolonged manipulation of any of said key members for preventing'repeated operation of said contact controlling device.

9, In a keyboard device, a plurality of key members operatively supported in a concentric alignment, a locking disc including appurtenances to cooperate with each of said key members to be shifted together with said locking disc upon the actuation of any one of said key members, and means associated with said locking disc effective during the shift disposition thereof and following the actuation of one of said key members to prevent the operation of any of the other of said key members.

10. In a keyboard device, a plurality of key members, a locking disc, cam means associated with said keymembers and said disc for rotating said disc into a locking position, and means for restoring said'disc to its normal position upon the release of an actuated key member.

11. A keyboard transmitter comprising a circular assembly of key members, a locking device actuable upon the depression of one of said key members to prevent the actuation of any other of said key members, a plurality of signal transmitting elements, each associated with one of said key members and conditionable by the actuation thereof, and a repeat signal preventing means comprising a blocking apparatus normally disposed to permit a selective disposition of one of said transmitting elements but shiftable immediately following a signal transmission to prevent the reconditioning of said conditioned one of said transmitting elements.

12. A keyboard transmitting apparatus comprising a synchronously regulated and continuously rotated shaft, a seeker carried by said shaft and capable of being reciproc'ated to effect alternative line controlling conditions, a plurality of signaling elements disposed along the path of said rotating seeker and individually conditionable to encounter said seeker and to cause its reciprocation thereby, means associated with said seeker for restoring conditioned ones of said signaling elements following their encounter with said seeker, and means for preventing the repeated conditioning of said elements.

13.. A transmitting mechanism comprising a continuously rotating shaft, a plurality of key members operatively supported in concentric alignment about said shaft, a plurality of signaling elements each associated with one of said key said disc.

members and disposed in concentric alignment about said shaft. a contact controlling member carried by said shaft, and revolvable through a path defined by said signaling elements, means under the control of each of said key members for moving one of said elements into the path of said revolvable member, and means associated with said member for automatically restoring moved ones of said signaling elements following their encounter with said member.

14. In a rotary switchcontrolling apparatus, a rotatable shaft, a plurality of character members, means carried by said shaft having itinerant communication with said character" members, a circuit breaker, a circuit breaker controlling device operable by said means when the latter'is conditioned by any of said members, and a portion carried by said means for restoring operated ones of said members.

15. In a keyboard control apparatus, a plurality of actuable manipulators, a shaft driven with cyclic regularity, a signaling switch, a supervisory member for controlling said switch, latchable means for prolonging the supervisory effects of actuating any of said manipulators, means carmeans to non-actuable position following an op- I eration of said signaling switch, and a device for rangement of centripetally urged interponents, a

shiftable disc having a blocking portion and an adjacent clearance presentable alternately for each of said interponents, a latch for holding said discso as to present its clearances to-said interponents, and means for releasing said latch after one of its said clearances has been entered by its interponent.

17. The combination set forth in claim 16 including a switch controller with which said latch I is integrally associated.

18. In a rotary control device, a circular arrangement of manipulators, an interponent associated with each of said manipulators, a rotatable shaft, means carried by said shaft having itinerant communication with each of said interponents, a shiftable disc carried by said shaft having a blocking portion and an adjacent clearance portion presentable alternatively for each of said interponents, a latch controlled by said ro- Q tary device for retaining said disc in a position so as to present its clearance portions to their associated interponents, and means operative following the actuation done of said manipulators for releasing said latch after the associated interponent has entered its clearance portion in 19; In a telegraph transmitting apparatus, a set of character members for initiating the transmission of corresponding character signals, interponent means conditionable by said character members for determining the cyclic periodicity 'of character signals, a transmitting distributor in-' cluding'a rotatable member, and means including said rotatable member and said interponent means for preventing the generation of partial signals.

20. In a telegraph transmitting apparatus, a set of character members each manually depressable for signal control actuation, a. rotary distributor, and interponent means conditioned and operated upon the depression of any one of said character 25 ried by said shaft for restoring said prolongation members for communicating through said rotary distributor a character variation of definite length indicative by its periodicity in the cycle'of said distributor of a corresponding signal characteristic.

21. In a signal transmitting apparatus, a keyboard comprising a set of key members, a distributor, a device traversing said distributor in regular cyclic rotation, means under the control of each of said key members for conditioning said device for operation before or alter a characteristic interval in its rotation, and means for preventing the conditioning oi' said device from being initiated during a precise instant in its rotation characterstic of a particularsignal.

LOUIS M. PO'I'IS. 

